Why? Because they expect that way to attract Japanese investments (never mind that Japan as economic power is doomed: radioactive countries with low transparency can't export).
Whatever the reasons, the move is the first one to actively export the Fukushima catastrophe outside Japan. Already the Japanese government has managed to lure with promises of money and demands of "solidarity" (solidarity through suicide?) many municipalities through Japan, even in Okinawa, rendering that way all the country contaminated with radiation.
Now they aim to export that pollution and the first useful fool to eat the bait has been Australia.
Source and more info at Ex-SKF.